Selection of reference genes for quantitative real-time RT-PCR on gene expression in Golden Pompano (Trachinotus ovatus)

Abstract

Golden pompano (Trachinotus ovatus) is an important economically fish species. In this study, with an aim to identify reliable reference genes for quantitative real-time PCR (qRT-PCR) in golden pompano, we evaluated the expression stability of eight housekeeping genes in the presence and absence of poly I:C stimulation in eight tissues. The PCR data was analyzed by geNorm and NormFinder algorithms. The results showed that the expression of all the examined genes exhibited tissue-dependent variations. When under normal physiological condition, geNorm and NormFinder identified B2M and 18S as suitable genes. When studying gene expression under conditions of poly I:C stimulation, the selection of the internal controls should be selected on a tissue basis. At 12 h stimulation, geNorm ranked Actin/UBCE, Actin/B2M, UBCE/B2M, Actin/UBCE, RPL13/B2M, UBCE/GAPDH, B2M/RPL13, and UBCE/B2M, respectively, as the most stably expressed genes in liver, spleen, kidney, gill, intestine, heart, muscle, and brain. Comparable ranking orders were produced by NormFinder. Similar results were obtained at 48 h stimulation. Taken together, these results indicate that B2M and 18S are the most stable gene across tissue types under normal physiological conditions. However, during poly I:C stimulation, no single gene or single pair of genes in the examined set of housekeeping genes can serve as a universal reference across all tissue types. If one gene is preferred, B2M, B2M, UBCE, Actin, B2M/RPL13, B2M, B2M, and RPL13 may be used in spleen, kidney, liver, gill, intestine, brain, muscle, and heart of golden pompano, respectively.